QUINCY – Joseph Koch, older brother of Quincy Mayor Thomas Koch and a city worker for 35 years, was found dead in his Randolph home Wednesday. He was 57.

The cause of death is under investigation and there is no evidence of foul play, the Norfolk County District Attorney’s Office said.

“We’re all just tremendously saddened and all our thoughts right now are with the entire Koch family during this incredibly difficult time,” Christopher Walker, a spokesman for Mayor Koch, said.

Peggie Krippendorf, a spokeswoman for Norfolk County District Attorney Michael Morrissey, said her office was notified of Koch’s death at about noon Wednesday. She said the death didn’t appear to be suspicious and a medical examiner will determine the cause.

Joseph Koch was one of seven children of Simone Koch and the late Richard Koch, a longtime city parks director. Koch, who grew up on Newbury Avenue in North Quincy, first joined the city’s park department in 1977, when his father was in charge.

He worked for six years as a laborer and equipment operator before transferring to the public works’ highway department in 1983. There he rose to the rank of foreman.

After two years in the private sector, Koch was hired by former Mayor James Sheets to rejoin the park department in 1996. His younger brother Thomas was head of the park department at the time.

Joseph Koch worked as a foreman and an arborist for the park department before moving back to the public works department about a year ago.

The Koch family is well-known in Quincy, rooted with Richard Koch’s creation of the Koch Club in 1948. The group was a charitable and recreation group that served thousands of the city’s youths.

Richard Koch also founded the city's modern Democratic party and was regional campaign secretary for John F. Kennedy's U.S. Senate campaigns.

Patrick Ronan may be reached at pronan@ledger.com or follow on Twitter @PRonan_Ledger.